Electric motor



March 31. 1925.

R. R. THOMPSON ELECTRIC uoTon Original Filed Nov. 22. 1919 Patented Mar. 3l, 192/5.

UNITED STATES ROBERT afrHoMrsoiv,

QECEASED; BY MARY W. THOMPSON, EXECUTRIX, OF LOS ANGELES, CALIFORNIA.

ELECTRIC MOTOR.

Original application illed November 22, 1919, Serial N. 339,788.

July 14, 1921.

To all whom t may concern:

Be it known that I, MARY W. THOMPSON, al citizen of the United States, residing at Los Angeles, in the county of Los Angeles, State of California, am the exeoutrix of the last will and testament of ROBERT R. THOMPSON, deceased, who did invent new and useful Improvements in yElectric Motors, of which the following is a specification.

This invention relates in its broader aspects to improvements ink electric motors of the rotating type; and more specifically to motors adapted for continued reversal of slow movement so as to effect a slow oscillatory motion. The specific form of the invention here illustrated and described is one particularly adapted for oscillatory movement of a signal; and its combination in a signal mechanism is described and claimed in the cO-pending application Ser. No. 339,788. led November 22nd 1919 for loscillating signals, ofwhich this application is a division. But I wish it to be understood that the invention is not limited to such specific use or combination. In this present application I desire to claim the motor mechanism independently of combination with a signal mechanism; but, as

the present speci lic embodiment of my motor` invention has been particularly designed for operating the oscillatory signal, and as ,the features of my motor invention can be well understood fromi a detailed description of this specific signal motor, I shall here give such a detailed description of the motor as asignal motor; without, however, intending to limit the motor to such combination or use.

The objects of the invention will be best understood from the following detailed specification; but it may be mentioned here that a general object is to produce an eiiicient motor havinga steady .torque and relatively heavy pullat veryslow operating speed and capable of operating :smoothly at slow speed; and to produce a motor capable of eflicient operation when reversed to produce an oscillatory motion. There are many other objects and corresponding features of accomplishment of the motor invention but they-will be best understood from. the following detailed description of a preferred form amtierender-mechanism as e @ated to Serial No. 484,68 7.

Divided and this application filed and embodied in an oscillatory signal mechanism; and for this purpose such mechanismsare illustrated inl the accompanying drawings, wherein F ig. 1 is a side elevation of the motor; Fig. 2 is a vertical longitudinal section taken as indicated by lines 2 2 on Fig. Fig. 3 is a transverse section taken as indicatedlby l1ne 3`3 on Fig. 2; and Fig. 4 isa fragmentary plan of the motor.

In the drawings the numeral 10 designates a `suitable base plate upon which the whole mechanism may be-mounted. Upon this base plate are erected a. pair of upright plates 11 and 12, which carry the major part of the motor mechanism and afford a mounting for control switches, etc. The hollow main shaft 13 of the motor mechanism is carried in anti-friction bearings 14.. in plates 11 and 12. The armature and field and commutator of the motor mechanism are mounted between the two plates 11 and 12; and the shaft 13 may extend behind the plate 12 to there carry controlling switch mechanism.

A non-magnetic bushing 20 is rigidly mounted on shaft 13 and carries a circular iron plate 21 upon which the several armature cores 22 are rigidly mounted and carried. These armature cores 22 extend axially from plate. 2l and are provided with windings 23. These windings 23 are connected together and connected yto conductor bars 24 which lead to commutator bars 25: the windings and connections being in the Ordina-ry and well known manner for a four pole motor. Conductor bars 24 and commuta-tor bars 25 are preferably integral; the commutator being formed by the bars 25, supported at their inner ends by` bars 24 which are screwed or otherwise set on the insulating plate or disc 26, and supported at their outer ends on a disc 27. A very sim(ple and inexpensive commutator is thus ma e.

At their ends, the armature cores 22 carry a magnetic armature ring 30, secured to the armature cores so as to be rigidly carried by the armature cores and so as to properly space the armature cores apart at their ends. This armature ring 30 is carried in proximity to the four fieldpoles 31 which are rigidly mounted uponsthe Plate 1l, These .feld poles are segmental n-'shape as shown in Fig., 3, and to them are secured the fieldl cores 32.v These field cores extend also axially of the machine 'and at their other ends carry four smaller pole pieces V33 which stand closeto the magnetic armatureV plate 2l. The magnetic gap between pole pieces n 33 and plate :2 is as small as practicable;

and the magnetic gap between pole pieces 31 and armature' ring 30 is also as' small Ias is practicable in a machine of this' characteri Armature ring 30 may have a .flange or lip 3% overhanging pole pieces 3l to reduce mag- Y netic"leali:age. Armature ring 30V and plate 21- are of iron of high reluctance; and ring` 30 isl yof small cross-section V'lhis is to prevent the magnetism generatedl bythe armature magnet coils-frein havinga magnetic and=33 rather than through parts 30 and 21.

There are four sets of magnetic field poles 3 1, 33. Each set is equipped with two cores 32 (in parallel) with suitable windingsA 35 which' are sok connectedtfor each pole) that the magnetism produced is either south or north asv the case may be, The reason for' this construction is toreduc'e radial dimension` of the' motor. The pole piecesV them# sel-'ves yare alternately of north and south polarity. v

Preferably onlyl two sets of brushes 40 are used on the commutator 25', the armature windings being cross-connected in the usual `and well lnown manner. Enough'has now f been described to show, without the necessity y of further detailed explanation, how the mechanism just described may act asar0- tating motor.v lt will be seen that thel armature, the revolving part, is relatively la-rgeg being so not only on account of the design in general, but alsov on account of its .being outside the field rather than inside. The armature vbeing thus relatively large, its several parts which are located at a compara# tively great distance from the center of r0- tationv lend :largely to the inertia of the machine, and facilitate its steadiness and smoothness of action at slow speed. This smoothness of action is also facilitated by the factl that'the field has eight poles and that' the armatiire hasfa large 'number of coils, all active at all'times. And, in spite of the' large number of coils, the armature' is easily repaired. vBeingat the outside; of -v pmaclii'ne, ,the armature c'oils may be easily removed; and one or even'several of them may be'removed', for repairs, etc., with--` out seriously impairing the action ofthe machine; the voltage on the machine being adjusted to suit the lesser number of arma-` ltu ture coilsl The field coils are relatively heavily wou-'nd so that there is" little' liability efftheir being damaged. 'The armature and ieldwi-ndings are usuallyl connected up in series.-

While I have described my machine in detail andA specificallyI I havegiven this particular and full descriptionof a preferred 4 form for the purpose of rendering my inventiorr'fully intelligible in its broad aswell as spe-c -ificfeatures and not'at all for the purpose of limiting' my' inventiont'o tliespe cific mechanismshere set forth. VRather do I conceive this invention to be broadin its scope and not limited except as appearsl -in the following'claims which are` to be interpreted" bioadly'to they invention as well as specifically to the' particular embodiment of it here described. 'f l Havingv described' a preferred form of the invention, I claim: a

l. A motor mechanism embodying a shaft, a stationary supporting member, a plurality of spaced field pole pieces supported on the member around7 the shaft, field cores and windings'feiitendingfrom the field pole pieces in` a direction parallel to the shaft, pole pieces mounted on the" ends' of thef'cores, 'a' magnetic ring plate mounted on the shaft near one'- set of pole pieces, armature' cores and' coils-mounted onthfev ringpl'at'e and extending parallel to the shaft, and an arma'- ture ring of magnetic metal mounted on the ends of the` armature cores andl supported thereby maras @the Seite aerien p01@- li'iear the second mentioned pole' pieces` and' with a small magnetic gap between said' poleI y pieces" and plate, armaturecoresV and coils mounted on the plate yin circular spaced ar"-` rangement .outside the field'coil's and eX# tending parallel to the 'sha-ft', and an armature ring of magnetic metal mounted on the se'cnd mentfi'ene'd 'pele piensa# ,armature coresi and-coils mon-'inedo the plte incir-r 'ends' of the armature cores and supported cular spaced arrangement outside the field coils and extending parallel to the shaft, and an armature ring of magnetic metal mounted on the ends of the armature cores and supported thereby near the first mentioned set of the field pole pieces, said armature ring having high magnetic reluctance.

t. A motor mechanism embodying a "shaft, a stationary supporting member, a

plurality of spaced field pole v pieces sup- )orted on the member around the shaft, field cores and windings extending from the field pole pieces in a direction parallel to the shaft, pole pieces mounted on and carried by the ends of the cores, a magnetic ring plate mounted on the shaft near the second mentioned pole pieces, and with a small magnetic gap between said pole pieces and plate, armature cores and coils mounted on the plate in circular spaced arrangement outside the field coils and extending parallel to the shaft, and an armature ring of magnetic metal mounted on the ends of the armature cores and supported thereby near the firstmentioned set of the field pole pieces, the pole pieces being segmental shaped and the armature ring lying close to them in an axial direction and having a flange Which overlies theirv circumferences, said armature ring having high magnetic reluctance.

A motor mechanism embodying a shaft, a stationary frame, a plurality of spaced field pole pieces arranged around the shaft, field coils and cores extending from the pole pieces parallel with the shaft, armature cores and coils mounted around the shaft and extending parallel to the shaft, and a magnetic armature ring connected to the armature cores and lying near the field pole pieces.

6. A motor mechanism embodying a shaft, a stationary frame, a plurality of spaced field pole pieces arranged around the shaft, field coils and cores extending from the pole pieces parallel with the shaft, armature cores and coils mounted around the shaft and extending parallel to the shaft, and a magnetic armature ring connected to the armature cores and lying near the field pole pieces, said armature ring being continuous and having high magnetic reluctance.

7. A motor mechanism embodying a shaft, a plurality of spaced field pole pieces arranged around the shaft, field coils and cores extending from the field pole pieces in a direction parallel to the shaft, pole pieces mounted on the extended ends of the cores, a magnetic arma-ture ring late arranged near the second mentioned eld pole pieces, armature cores and coils mounted on the plate and extending therefrom parallel to the shaft, and a magnetic armature ring on the extended ends of the armature cores near the first mentioned field pole pieces.

8. A motor mechanism embodying a shaft, a plurality of spaced field pole pieces arranged around the shaft, eld coils and cores extending from the field pole pieces in a direction parallel to the shaft, pole pieces mounted on the extended ends of the cores, a magnetic armature ring plate ar ranged near the second mentioned field pole pieces, armature cores and coils mounted on the plate and extending therefrom parallel to the shaft, and a magnetic armature ring on the extended ends of the armature cores near the first mentioned field pole pieces,

said armature ring and plate having high magnetic reluctance.

9. A motor mechanism embodying a stationary frame and a shaft, and two elements, one mounted on the frame and the other on the shaft; each element comprising a set of circularly spaced cores arranged around and extending parallel With the shaft, and windings around the several cores; one element having separated pole pieces at the ends of its cores, and the other element having at the ends of its cores a continuous magnetic ring arranged close to the pole pieces and of a material having relatively high magnetic reluctance.

In Witness that I claim the foregoing I have hereunto subscribed my name this 6th day of July, 1921.

MARY W. THOMPSON, Emeoutffz'm of Robert R. Thompson, deceased. 

